A wave of targeted attacks on soldiers, police, traffic officers and senior officials is steadily picking off the custodians of Iraq's streets at rates that are nearing the darkest days of the insurgency, according to security commanders.

As of last Monday 710 Iraqis had been killed this year with silenced pistols or rifles. At least 600 more had been killed by magnet bombs placed under the cars of officials, according to Baghdad's Major Crimes Unit. Hundreds more have been injured.

The killings have increased sharply in the past four months amid fears that the ongoing failure to form a government in Baghdad is fuelling a worsening security vacuum.

Police colonel Yassir Khadier had heard the warnings from his superiors to look carefully under cars for bombs. He had even given orders to his subordinates to be prudent. But on 6 October a magnet bomb fixed underneath his driver's seat destroyed his legs. They were later amputated. In his bed in the Khadimeyah hospital in northern Baghdad, Khadier held back tears. "They found me, somehow," he said of the unknown militants who lurk in the city's streets. "I look most days. I didn't yesterday."

The director of the emergency ward, Dr Haithem Kadouri, said he had seen a significant increase in blast injuries like those suffered by Khadier. "I would say that in terms of targeted bombings like these and shootings we are seeing the same numbers of casualties as we were in 2007. It has got bad again."

Magnet bombs have become a feature of daily life in Baghdad, where hundreds of checkpoints are being equipped with mirrors in the hope of detecting explosives fixed to a car's underbelly among the half a million vehicles that snarl the capital's streets every day.

They have limited success, according to several of the traffic police given the task of finding the bombs.

"More than 35 of my colleagues have been killed recently," said a traffic officer, Louay Shehab, 34, in downtown Karrada. "They have been killed by these sticky bombs and by pistols with silencers.

"Our director met us last week and warned us again to be careful. We've been given weapons to protect ourselves, but the situation is critical. Its 2007 again."

A second traffic officer, Omar Sabah, said he was now almost too scared to turn up to work.

"I have worked with the police since 2004 and this is the most dangerous atmosphere in all of that time. Al-Qaida have very accurate information. They are not random attacks. They are organised. Al-Qaida are seeking their revenge. They want to destroy the government."

Ali Sayed, 30, an army lieutenant at a nearby checkpoint, agreed. "The delay in forming the government is creating this atmosphere. I cannot hide my concerns. Every day, three or four of my colleagues are being killed."

Monthly numbers of violent deaths increased throughout the summer to levels not seen for two years in Iraq. However, security officers and officials accounted for a large number of them, unlike the bloodiest days of the insurgency in 2006, when civilians were targeted by sectarian death squads.

Intelligence officials believe that those who are ordering the attacks on officials have decided not to send car bombs and suicide bombers for now, because they believe they are leading Iraq towards anarchy.

"People fear lawlessness," said the director of the interior ministry's intelligence division, General Hussein Kamal. "They don't fear widespread sectarianism for now, but they do fear that they won't be safe in their homes from criminals."

Kamal claimed that supporters of the ousted Ba'ath party were the key drivers of the violence. "Don't forget there were 500,000 members of the Ba'ath party in the security forces at least when the regime fell. We may have got rid of some, but we haven't found them all."

Across town the director of the Major Crimes Unit, Major General Sabah al-Shebli, had a different view. "It's al-Qaida," he said. "It's nearly always them. But sometimes there are other groups," he continued — alluding to Shia militias whose members are again active in parts of east Baghdad.

Shebli thumbed through a bulky report his men had made of recent attacks. Three of his officers were killed by magnet bombs this week alone. He pointed out the type of bomb that had killed them, a tin box around the size of a notebook, filled with explosives and a round magnet. A mobile phone is often attached to the bomb and it is detonated by a caller phoning the number.

"The bomb squads go around the streets at night looking for government number plates [on cars]. We keep telling people to check, but it is not sinking in."

Kamal echoed this complaint, but said the bombers knew who they were looking for. "It's targeted," he said.